Abstract: This paper surveys representation and processing theories arising out of conceptual dependency theory. One of the primary characteristics of conceptual dependency was the notion of a canonical form, built out of a small number of primitive representations. Although the notion of primitives has largely been lost in subsequent work, many other of the basic notions of CD have remained. In particular, the idea of building representations around inferential capabilities has prevailed in this family of research. The result is a set of representational structures, all of which are highly knowledge-intensive. The use of these structures in various processing theories has led to knowledge-based theories of language understanding, planning, reasoning and other tasks, which have contrasted sharply with the traditional search-oriented approaches used in other systems.